Questions tagged [proof-of-work]

This tag should be used for questions regarding how Proof of Work works and Proof of Work algorithms. Proof of Work is a scheme where a 3rd party can verify that someone performed at least a certain amount of work to produce something. This is used in Bitcoin mining.

According to this answer: https://bitcoin.stackexchange.com/a/58908/41513 a Byzantine Fault Tolerant (BFT) consensus threshold is 1/3, that is contrary to belief that the Bitcoin network is secure (...

i am reading the proof-of-work (aka: pow, target threshold, difficulty, etc.); my understanding is that pow adds a requirement to validate block headers, so that both benign and malign nodes need a ...

I am learning to develop a new cryptocurrency on my own, for the same i decided to develop a Proof-Of-Stake coin, I forked the Okcash for this purpose.
And was able to change the coin according to my ...

Bitcoin and Ethereum both use proof-of-work (PoW) consensus mechanism. One of differences between Bitcoin Pow and Ethereum PoW is difficulty level, meaning that while in bitcoin block generation rate ...

Assuming Bitcoin had a different method for selecting winning nodes and controlling block time creation, please describe step-by-step how the Bitcoin network would be vulnerable to various attacks. ...

So from what I understand, Bitcoin's PoW is prone to 51% attack, but as a distributed system it is also prone to BFT's 1/3 attack right? I think it's mathematically proven that in a distributed system,...

I am doing the Coursera course on Bitcoin and Crypto tech, and there is a formula defined : Goodput = Throughput * Success Rate.
'Throughput' is defined as how quickly we are finding blocks, whilst '...

Bitcoin's block time is about 10 minutes while that of Ethereum is 15 secs. Both are using PoW at this moment, right? How come Ethereum's block time is so short compared to Bitcoin? Is hashing a lot ...

I've read at a few places that the nodes validate transactions in a linear fashion, i.e. after node A validates, then node B, etc. (which is also the reason, as claimed by many, why blockchain suffers ...

From what I understand, we need mining to validate the block, we need the proof of work to limit the number of miners can add a block, and we need the block interval to give time to the new block to ...

I am talking about miners centralization with large pools. Is it a problem?
I think there are some possible ways to prevent miners from pooling. For example add miner signature to the block header, ...

I've been reading about the vulnerabilities of PoW crypto, and there's a part of it that I don't understand.
Suppose I wanted to stage a 51% attack on Bitcoin (not really feasible, but bear with me). ...

I am writing a project on cryptocurrencies. As a part of this project, I thought of a new token for web services exchange. I tried to combine PoW and PoS and here is what I have. I called it Proof-of-...

Bitcoin's pow is sha256, the hash of header is taken and check against a given target to see whether it is smaller than the target, this can be easy seen as block hash starts with zeros. But how does ...

Are there other concepts for the validation of the next added block to the blockchain beside POW, POS etc.?
Of cource there are, but is there a methode that is shining out of the mass?
A methode that ...

In this paper "Information Propagation in the Bitcoin Network" the authors measured stale blocks in bitcoin and got a rate of 1.69% stale blocks. This is due to block propogation delay.
The authors ...

My question: Do the blocks in a blockchain without proof-of-work (i.e. a permissioned blockchain) have to be linked together via a cryptographic hash?
Longer version of my question:
(Please correct ...

I am new to block chain, In PoW, I know a puzzle is given to the miners to solve and the miner who solve the puzzle and find the nonce first will create the block.
But I don't understand why there is ...

I’m bit stuck in the concept of mining.
What are the hashes that need to be created in each block and the chain? Let’s say that we have block A - B - C forming a chain.
One source said that we need ...

I have some problems understanding the flow of consensus mechanism, so far I know, In PoW when validating a transaction the miners will compete with each other to solve a puzzle, the miner who find ...

I'm trying to get a handle on the Stratum mining pool protocol. If I set up a mining pool client, I will initially get something to work on. Let's say it takes me a while (e.g. an hour) to solve the ...

As new transactions are broadcasted, the nodes keep them in a pool of unconfirmed transactions.
One node will add it to a block as soon as it finds a proof of work. At the same time many other nodes ...

I wanted to try and better understand how a Stratum client communicates with a pool, so I was experimenting with this NodeJS project -- https://github.com/arnabk/stratum-client/blob/master/README.md . ...